NATIONAL STORM SUMMARY

 

JULY 2012

 

8^th-14^th…Heavy rains developed in the Deep South on Monday, while scattered showers and thunderstorms stretched along a frontal boundary in the Mid-Atlantic states. Heavy rains and strong thunderstorms developed across the Lower Mississippi River Valley as strong onshore flow persisted from the Gulf of Mexico. Some areas of southern Louisiana saw rainfall totals from 3 to 4 inches. Flooding became of concern in these areas. Heaviest rainfall was reported in Fort Polk, Louisiana with a mid-day total of 4.66 inches of rain. These storms have not yet turned severe, but were likely to produce some strong winds and possibly some large hail. To the north, a frontal boundary lingered over the Mid-Atlantic states and extended over the Mid-Mississippi River Valley. Additional moisture from the Atlantic Ocean fed energy into this system, which allowed for thunderstorms to develop across most of Maryland and parts of the Carolinas and the Virginias. Strong winds were reported up to 56 mph in South Hill, Virginia, and rainfall totals ranged from 1 to 2 inches across the region. Meanwhile in the Plains, a trough of low pressure moved off the Central Rockies and into the Central Plains. The leading edge of this system pulled moisture in from the South, which triggered showers and thunderstorms across the southern and central Plains. Heaviest rainfall was reported in Pratt, Kansas with a mid-day total of 1.95 inches of rain.

 

8^th-14^th…Eastern Texas and the Southeast saw more heavy rain on Friday, while monsoonal moisture triggered strong storms over the West. A trough of low pressure over the western Gulf of Mexico pushed more moisture onshore. This brought more showers and thunderstorms to eastern Texas and the Lower Mississippi River Valley. Flooding remained of concern since some areas saw another 2 to 4 inches of rain. Heaviest rainfall was reported in Beaumont, Texas with a mid-day total of 3.96 inches of rain. Just north of this activity, a frontal boundary lifted northward through the Eastern Valleys. This pushes warm and humid air northward, which created favorable conditions for thunderstorm development. These storms have not turned severe but areas of heavy rainfall developed. Heaviest rainfall was reported in Clemson, South Carolina with a mid-day total of 2.10 inches of rain.

 

15^th-21^st…Hot, humid, and unsettled weather continued in the East on Wednesday. Scattered showers and thunderstorms developed along a frontal system extending from the Upper Midwest through the Ohio River Valley and ahead of a cold front extending through New England and the Lower Great Lakes. As of this afternoon, there have been numerous quarter to ping pong ball sized hail (1.00 to 1.50 inches in diameter) and high wind reports with downed trees and wires in these regions.

Two cold fronts brought more thunderstorm activity to the Eastern US on Friday. One front extended from the Northeast and into the Gulf of Mexico, which created widespread showers and thunderstorms. Some of these storms turned severe with heavy rainfall and strong winds. Heaviest rainfall was reported in Alpine, Texas with a mid-day total of 2.61 inches of rain. Behind this system, another front moved over the Upper Midwest and Great Lakes, into the Midwest. This system also created showers and thunderstorms throughout the day, some of which also turned severe. There have been multiple reports of large hail from Michigan, while wind gusts up to 60 mph were reported in Fishers, Indiana.

 

29^th-31^st…An active weather pattern developed across the nation on Monday as monsoonal activity continued in the West, a frontal system dropped into the Upper Midwest, and a trough of low pressure lingered over the eastern third of the nation. In the West, a plume of subtropical moisture from the Pacific Ocean streamed inland from the southwest across southeastern California and the Four Corners through the day. Ample moisture over these areas combined with waves of energy pushing through the region translated into heightened monsoonal activity during the afternoon with areas of rain and thunderstorms. Flash Flood Watches remained in effect for areas from southeastern California and northwestern Arizona through southern Utah, while a Flash Flooding became possible for parts of the south-central Mohave County in northwestern Arizona.

 

Jim G. Munley, jr.
http://www.jimmunleywx.com